1. Field of the Invention
The invention relates to a coupling assembly with pipe sockets of fluid-holding parts to be joined, such as fluid lines and tanks, wherein the pipe sockets are each provided with a locking rib that is coaxial with their center axis, behind which locking rib a groove is formed and which locking rib has a conical front flank that is coaxial with the center axis and a radial rear flank, wherein the front flank of one of the locking ribs is opposite the front flank of the other locking rib, and the rear flank of at least one locking rib forms one of the walls of the adjacent groove, and with a steel spring band, which is largely circularly curved over more than 240° and whose axial ends have inwardly directed flanges with an inner edge that has the approximate form of a circular arc and is coaxial with the center axis, which flanges engage behind the locking ribs and are interrupted at least on the side of the spring band that lies opposite the circumferential ends of the spring band, and wherein the pipe sockets are partially fitted into each other, and the parts of the pipe sockets that are fitted together are sealed from each other by at least one gasket.
The invention also relates to a coupling assembly with pipe sockets of fluid-holding parts to be joined, such as fluid lines and tanks, wherein the pipe sockets are each provided with a locking rib with a radial rear flank, which locking rib is coaxial with the center axis of the pipe sockets, wherein the rear flank of at least one of the locking ribs bounds a groove, and with a steel spring band, which is largely circularly curved over at least 240° and whose axial ends have inwardly directed flanges with an inner edge that has the approximate form of a circular arc and is coaxial with the center axis, which flanges engage behind the locking ribs and are interrupted at least on the side of the spring band that lies opposite the circumferential ends of the spring band, and wherein the pipe sockets are partially fitted into each other, and the parts of the pipe sockets that are fitted together are sealed from each other by at least one gasket.
2. Description of the Related Art
In the coupling assembly described above, the spring band is expanded to place it radially onto the locking ribs of the pipe socket. However, the pipe sockets cannot be inserted axially into the spring band, as in the case of a plug coupling, because one of the flanges moves axially into the groove behind one of the locking ribs until the other flange rests against this locking rib, and there is no longer any free space to receive the other locking rib between the flanges. Other well-known coupling assemblies with a spring band, e.g., the spring band disclosed in DE 198 18 562 C1 or in DE 198 00 283 C1, which is a so-called “shaped clip”, serve the purpose of joining pipes which are provided at their ends with locking ribs in the form of flanges, whose flanks facing away from the ends are conical. The spring band consists of steel sheet. Its lateral edges are bent inward at an angle of less than 90° to form the flanges. The angle corresponds to the cone angle of the flanges at the ends of the pipe. A slit between the ends of the spring band can be bridged by a snap closure or joint closure. The joint opposite the slit is formed by the material of the spring band in the vicinity of an interruption of the flange of the spring band as a type of “film joint” or by another joint closure. During the joining of the pipes, the spring band is placed around the flanges of the pipes with the closure open (or with the closures open), and then the closure or each closure is closed again. During this operation, the flanges of the spring band come to lie against the conical flanks of the pipe flanges, so that the ends of the pipes are drawn together. Although the steel sheet of the spring band is flexible in the vicinity of the joint in the embodiment with a “film joint” (DE 198 18 562 C1), it does not exert any radial clamping force on the pipes. The clamping force is based solely on the tension force of the closure or closures. Therefore, a coupling assembly with a shaped clip is not suitable as an easily closed plug coupling, in which the ends of the pipe only need to be axially inserted into the shaped clip, and the flanges lock into place behind the locking ribs on the pipes during the insertion process to produce the connection. The manufacture of the spring band with a snap closure, which is formed as a single part with the spring band, requires expensive punching and bending tools. The manufacture of the spring band with a joint closure additionally requires the formation and mounting of the joint closure.
In a plug coupling of the type disclosed in EP 1 378 701 A1, the coupling consists of elastic plastic. It has two oval rings that are joined by two diametrically opposite webs. The rings have two inner detents. When the pipe ends are inserted into the rings, the rings are elastically expanded by locking ribs on end sections of the pipes until the detents of the rings snap into place behind the locking ribs. In the coupled state, a clearance remains between the ring regions with the smaller radius of curvature and the pipes, and this clearance allows radial cooperation of the rings for decoupling. The material of this coupling is limited to plastic. An expensive extrusion die is needed to produce this coupling. Due to the wide spaces between the webs and the decoupling clearance between the rings and the pipes, there is the possibility that the end sections of the pipes inserted into the coupling could soil the coupling. This can make repeated coupling and decoupling difficult.